Verification Supporting Apparatus, Verification Supporting Method, and Computer Product

1. A non-transitory computer-readable recording medium storing therein a verification supporting program that causes a computer to execute: recording in a memory, a DIRW matrix in which, among four states including Declare, Initialize, Read, and Write, a state transition that has a possibility of occurring in a register included in a circuit to be verified and information concerning validity of a path corresponding to the state transition are set; acquiring implementation information of the circuit to be verified, a verification scenario that is representative of contents of verification for the circuit to be verified, and a register list that indicates attributes of registers included in specifications of the circuit to be verified; creating, from the implementation information and the register list acquired at the acquiring, a control data flow graph that includes a control flow graph having a flow of control for implementation of the circuit to be verified described therein and further having a data flow graph written therein, the data flow graph having a flow of data in the control flow graph described therein; extracting, from the control data flow graph created at the creating, a data flow graph that has described therein a register; extracting, from the data flow graph extracted at the extracting the data flow graph, a path indicating the flow of data concerning the register; identifying, based on the data flow graph, the state transition of the path extracted at the extracting the path; determining whether the state transition identified at the identifying is set in the DIRW matrix; calculating, if at the determining, the state transition of the path has been determined to be set in the DIRW matrix, a value that can be substituted as a parameter in the register connected to the path, the verification scenario acquired at the acquiring and the control data flow graph being used in the calculating; and creating a verification scenario having a parameter that is obtained by setting the value calculated at the calculating in the verification scenario.

2. The non-transitory computer-readable recording medium according to claim 1 , wherein the extracting the data flow graph includes extracting a data flow graph that has described therein an internal register that is inaccessible from outside the circuit to be verified and is among the registers included in the circuit to be verified, the extracting the path includes extracting a path indicating the flow of data concerning the internal register, and the calculating includes calculating, if at the determining, the state transition of the path has been determined to be set in the DIRW matrix, a value that can be substituted as a parameter in the internal register connected to the path, the verification scenario acquired at the acquiring and the control data flow graph being used in the calculating.

3. The non-transitory computer-readable recording medium according to claim 2 , wherein the creating the control data flow graph includes creating, from the implementation information and the register list, the control data flow graph of the circuit to be verified, if at the acquiring, a verification scenario verifying a limited scope in the circuit, the implementation information, and the register list are acquired, and the calculating includes calculating the parameter using the verification scenario for which the scope to be verified is limited and the control data flow graph.

4. The non-transitory computer-readable recording medium according to claim 2 , wherein the extracting the data flow graph includes extracting, from the control data flow graph created at the creating unit, a data flow graph that has described therein the flow of data concerning an arbitrary register to be verified, the extracting the path includes extracting, from the data flow graph extracted at the extracting the data flow graph, a path indicating the flow of data concerning the arbitrary register to be verified, the identifying includes identifying, based on the data flow graph, the state transition of the path extracted at the extracting the path, the determining includes determining whether the state transition identified at the identifying is set in the DIRW matrix, and the calculating includes calculating a parameter that can be substituted in the arbitrary register to be verified, by using, as a path to be verified of the arbitrary register, the path for which the state transition is determined at the determining to be set in the DIRW matrix, the calculating further being based on the verification scenario acquired at the acquiring and the control data flow graph.

5. The non-transitory computer-readable recording medium according to claim 1 and storing therein the verification supporting program that further causes a computer to execute: extracting, as an implementation-dependent register that is mounted depending on configuration of the implementation, a register that is among registers described in the control data flow graph and not included in the register list acquired at the acquiring, wherein the extracting the data flow graph includes extracting a data flow graph that has described therein the implementation-dependent register extracted at the extracting the register, the extracting the path includes extracting a path indicating the flow of data concerning the implementation-dependent register, and the calculating includes calculating, if at the determining, the state transition of the path has been determined to be set in the DIRW matrix, a value that can be substituted as a parameter in the implementation-dependent register connected to the path, the verification scenario acquired at the acquiring and the control data flow graph being used in the calculating.

6. The non-transitory computer-readable recording medium according to claim 5 , wherein the creating the control data flow graph includes creating, from the implementation information and the register list, the control data flow graph of the circuit to be verified, if at the acquiring, a verification scenario verifying a limited scope in the circuit, the implementation information, and the register list are acquired, and the calculating includes calculating the parameter using the verification scenario for which the scope to be verified is limited and the control data flow graph.

7. The non-transitory computer-readable recording medium according to claim 5 , wherein the extracting the data flow graph includes extracting, from the control data flow graph created at the creating unit, a data flow graph that has described therein the flow of data concerning an arbitrary register to be verified, the extracting the path includes extracting, from the data flow graph extracted at the extracting the data flow graph, a path indicating the flow of data concerning the arbitrary register to be verified, the identifying includes identifying, based on the data flow graph, the state transition of the path extracted at the extracting the path, the determining includes determining whether the state transition identified at the identifying is set in the DIRW matrix, and the calculating includes calculating a parameter that can be substituted in the arbitrary register to be verified, by using, as a path to be verified of the arbitrary register, the path for which the state transition is determined at the determining to be set in the DIRW matrix, the calculating further being based on the verification scenario acquired at the acquiring and the control data flow graph.

8. The non-transitory computer-readable recording medium according to claim 5 , wherein the extracting the data flow graph includes extracting a data flow graph that has described therein an internal register that is inaccessible from outside the circuit to be verified and the implementation-dependent register extracted at the extracting the register, the extracting the path includes extracting a path indicating the flow of data concerning the internal register and the implementation-dependent register, and the calculating includes calculating, if at the determining, the state transition of the path has been determined to be set in the DIRW matrix, a value that can be substituted as a parameter in the internal register or as a parameter in the implementation-dependent register connected to the path, the verification scenario acquired at the acquiring and the control data flow graph being used in the calculating.

9. A verification supporting apparatus comprising: a recording unit that records a DIRW matrix in which, among four states including Declare, Initialize, Read, and Write, a state transition that has a possibility of occurring in a register included in a circuit to be verified and information concerning validity of a path corresponding to the state transition are set; an acquiring unit that acquires implementation information of the circuit to be verified, a verification scenario that is representative of contents of verification for the circuit to be verified, and a register list that indicates attributes of registers included in specifications of the circuit to be verified; a CDFG creating unit that, from the implementation information and the register list acquired by the acquiring unit, creates a control data flow graph that includes a control flow graph having a flow of control for implementation of the circuit to be verified described therein and further having a data flow graph written therein, the data flow graph having a flow of data in the control flow graph described therein; a DFG extracting unit that, from the control data flow graph created by the CDFG creating unit, extracts a data flow graph that has described therein a register; a path extracting unit that, from the data flow graph extracted by the DFG extracting unit, extracts a path indicating the flow of data concerning the register; an identifying unit that, based on the data flow graph, identifies the state transition of the path extracted by the path extracting unit; a determining unit that determines whether the state transition identified by the identifying unit is set in the DIRW matrix; a calculating unit that, if the determining unit has determined that the state transition of the path is set in the DIRW matrix, calculates using the verification scenario acquired by the acquiring unit and the control data flow graph, a value that can be substituted as a parameter in the register connected to the path; and a scenario creating unit that creates a verification scenario having a parameter that is obtained by setting the value calculated at the calculating in the verification scenario.

10. The verification supporting apparatus according to claim 9 , wherein the DFG extracting unit extracts a data flow graph that has described therein an internal register that is inaccessible from outside the circuit to be verified and is among the registers included in the circuit to be verified the path extracting unit extracts a path indicating the flow of data concerning the internal register, and the calculating unit, if the determining unit has determined that the state transition of the path is set in the DIRW matrix, calculates using the verification scenario acquired by the acquiring unit and the control data flow graph, a value that can be substituted as a parameter in the internal register connected to the path.

11. The verification supporting apparatus according to claim 9 further comprising: a register extracting unit that extracts, as an implementation-dependent register that is mounted depending on configuration of the implementation, a register that is among registers described in the control data flow graph and not included in the register list acquired by the acquiring unit, wherein the DFG extracting unit extracts a data flow graph that has described therein the implementation-dependent register extracted by the register extracting unit, the path extracting unit extracts a path indicating the flow of data concerning the implementation-dependent register, and the calculating unit, if the determining unit has determined that the state transition of the path is set in the DIRW matrix, calculates using the verification scenario acquired by the acquiring unit and the control data flow graph, a value that can be substituted as a parameter in the implementation-dependent register connected to the path.

12. The verification supporting apparatus according to claim 11 , wherein the DFG extracting unit extracts a data flow graph that has described therein an internal register that is inaccessible from outside the circuit to be verified and the implementation-dependent register extracted by the register extracting unit, the path extracting unit extracts a path indicating the flow of data concerning the internal register and the implementation-dependent register, and the calculating unit, if the determining unit has determined that the state transition of the path is set in the DIRW matrix, calculates using the verification scenario acquired by the acquiring unit and the control data flow graph, a value that can be substituted as a parameter in the internal register or as a parameter in the implementation-dependent register connected to the path.